Here's some information to ponder concerning grayscale images. "Value" is a
very important aspect of color. All the computer colors depend on Red, Green
and Blue light. However, Green is brighter than Red. So life would be
simpler if we lived in a computer world which had number triples in GRB
order. There are 5 different images created here. Because they are being
timed, there are two of each image. Compare RGB and GRB. Compare Gray
RGB and Gray GRB . The final image is a different strategy for obtainin a
grayscale image.
require 'viewmat'
at2=: 13 :'([:{:"1 *.) j./"1 y'
RGB=: 255* #:i.8
GRB=:1 0 2{"1 RGB
we=: 13 :'<.0++/"1[0.3 0.59 0.11*"1 y'
gray=: 13 :'3#"0 we y'
ts=: 6!:2 , 7!:2@]
ts 'RGB viewmat (D=.at2"0 /~ i:500);''RGB Clock'''
ts 'GRB viewmat (D=.at2"0 /~ i:500);''GRB Clock'''
ts '(gray RGB) viewmat (D=.at2"0 /~ i:500);''Gray RGB Clock'''
ts '(gray GRB) viewmat (D=.at2"0 /~ i:500);''Better Gray GRB Clock Linda
Alvord'''
RM=: (# # +/ % #)"1
ts 'RM(3#"0 i.255) viewmat (D=.at2"0 /~ i:500);''Better Gray Clock Raul
Miller'''
I am looking for the bes possible way to introduce the topic of color images
and their grayscale images. Also, in the next examples I would like to show
the value of "value" in analyzing numeric data. Please send any ideas that
might be useful.
Linda
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Linda Alvord
Sent: Monday, March 31, 2014 12:35 AM
To: [email protected]
Subject: Re: [Jprogramming] Challenge 14; Colorful Creations
require 'viewmat'
at2=: 13 :'([:{:"1 *.) j./"1 y'
]P8=: 255* #:i.8
]Q8=:1 0 2{"1 P8
ro=: 13 :'<.0.5+y'
we=: 13 :'+/"1[0.3 0.59 0.11*"1 y'
gray=: 13 :'3#"0 ro we y'
ts=: 6!:2 , 7!:2@]
ts '(gray P8) viewmat (D=:at2"0 /~ i:1000);''Better Gray Clock'''
RM=: (# # +/ % #)"1
grayRM=:RM P8
ts 'RM(3#"0 i.255) viewmat D;''Better Gray Clock Raul Miller'''
Q8=:1 0 2{"1 P8
grayLA=: 13 :'1 0 2{"1 y'
ts '(gray Q8) viewmat D;''Better Gray Clock Linda Alvord'''
Both images look quite good. Is there some way to determine which is the
better image or are they the same?
Linda
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Raul Miller
Sent: Sunday, March 30, 2014 4:17 PM
To: Programming forum
Subject: Re: [Jprogramming] Challenge 14; Colorful Creations
Like this?
(3#"0 i.255) viewmat D;'Grade from white to black, clockwise from North'
Thanks,
--
Raul
On Sun, Mar 30, 2014 at 4:09 PM, Linda Alvord
<[email protected]>wrote:
> Here's another solution:
>
> RM=: (# # +/ % #)"1
> grayRM=:RM P8
> (grayRM) viewmat D;'Gray Clock 1 Raul Miller'
>
> grayDL-:grayRM
>
> Actually both roads lead to the same Rome.
>
> Raul. If you look at your clock, can you make a better clock face that
> grades from white to black going clockwise from North?
>
> Linda
>
>
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Linda
> Alvord
> Sent: Sunday, March 30, 2014 3:29 PM
> To: [email protected]
> Subject: Re: [Jprogramming] Challenge 14; Colorful Creations
>
> Here's the first entry from David Lambert.
>
> grayDL=: P8 +/ .*3 3$1r3
> (grayDL) viewmat D;'Gray Clock 1 Dave Lambert'
>
> Imagine that his image is the face of a clock. What I am looking for in
> Example 2 is a clock face that will be a better gradient from white to
> black
> if you start at noon and travel around the clock going clockwise all the
> way
> to 12 again.
>
> Linda
>
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Linda
> Alvord
> Sent: Sunday, March 30, 2014 12:26 PM
> To: [email protected]
> Subject: [Jprogramming] Challenge 14; Colorful Creations
>
> Challenge 13 was posted on 7/2/2012. It must be time for another. Here
> is
> challenge 14:
> Copy the code below into a new temp in jqt. Now run all lines of the
> code.
>
> require 'viewmat'
>
> at2=: 13 :'([:{:"1 *.) j./"1 y'
> viewmat (D=:at2"0 /~ i:300);'Arctan'
> ]P8=: 255* #:i.8
> P8 viewmat D;'Challenge Example 1'
>
> NB. When you run the code above, you will create 2 bmp images.
> NB. D is the numeric array of data and
> NB. P8 is the 8 color palette.
>
> NB. Here is the challenge:
> NB. Design a function called "gray" that will convert Example 1 into a
> grayscale image.
>
> NB. gray=:
>
> (gray P8) viewmat D;'Gray Challenge 1'
>
> Please provide an expression that will when inserted for gray above
will
> produce the grayscale image.
>
> Pasting the bmp as an inserted image works in emails, but will be rejected
> in the forum.
>
> Have fun.
>
> Linda
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